The cost of computing and networking technologies have fallen to the point where computing and networking capabilities can be built into the design of many electronic devices in the home, the office and public places. The combination of inexpensive and reliable shared networking media with a new class of small computing devices has created an opportunity for new functionality based mainly on the connectivity among these devices. This connectivity can be used to remotely control devices, to move digital data in the form of audio, video and still images between devices, to share information among devices and with the unconstrained World Wide Web of the Internet (hereafter “Web”) and to exchange structured and secure digital data to support things like electronic commerce. The connectivity also enables many new applications for computing devices, such as proximity-based usage scenarios where devices interact based at least in part on geographical or other notions of proximity. A prevalent feature of these connectivity scenarios is to provide remote access and control of connected devices and services from another device with user interface capabilities (e.g., a universal remote controller, handheld computer or digital assistant, cell phones, and the like). These developments are occurring at the same time as more people are becoming connected to the Internet and as connectivity solutions are falling in price and increasing in speed. These trends are leading towards a world of ubiquitous and pervasive networked computing, where all types of devices are able to effortlessly and seamlessly interconnect and interact.
In the above ubiquitous and pervasive networked computing scenarios, the devices desirably can interoperate on an ad hoc peer-to-peer networking connectivity basis. Such a peer networking connectivity model enables any networked device to initiate a communication with any other networked device, without having established a prior relationship or maintaining a persistent relationship between the devices. This peer networking connectivity also allows multiple devices to establish one or more connections with a single device, and it allows for a device to be capable of both initiating and accepting connections to/from other devices.
The prevalent model for device connectivity, however, has been that of host-peripheral connectivity, typified by the personal computer and its many peripheral devices (e.g., data storage drives, user input devices, displays, printers, scanners, etc.) connected via various buses (e.g., PCI, VESA, AGP, Microchannel, ISA, EISA, USB), ports (e.g., serial, parallel), and connectors (e.g., PS/2 connector). This host-peripheral connectivity model is characterized in that the host and peripherals typically have persistent relationships and stable configurations. This persistent relationship is created, by example, through a set-up and configuration process through which appropriate driver software is installed by a user or administrator onto the host for use in controlling the peripheral, and updating the host's configuration to include peripheral device settings. Such persistent configured relationships with a user installation/configuration experience are generally inappropriate to the ubiquitous and pervasive computing environment where portable and mobile devices desirably can instantly connect and interact with other computing devices in their environment without having established prior or persistent relationships.
More specifically, two common computing networks where many of these small, network-capable computing devices are expected to be used include the home and small office. Such networks are commonly not actively managed by experienced administrators. In fact, due to the lack of networking experience of a large majority of the users of these networks, lengthy, complex and/or involved user installation and setup experiences pose a significant impediment to adoption and penetration of such networks and devices into homes and small offices.
Further, the establishment of persistent relationships with other devices in the configuration of these small, network-capable computing devices is inappropriate to many usage scenarios. For example, portable computing devices (such as a handheld computer or digital assistant, cell phones, and the like) may be used to access information (such as transportation departure/arrival times, store locations, etc.) from other devices on networks in public places (such as malls and airports). Not only would a user installation/configuration experience upon each such use pose an inconvenience, but the establishment of persistent configuration information poses configuration management issues and consumes device resources. As another example, devices (such as printers, scanners, monitors and etc.) on an office or home network may interact with many portable computing devices (such as the laptops, cameras, and other equipment of the mobile professional) that are introduced into its network. Again, in device connectivity models requiring establishing persistent device relationship configurations, such one-time and occasional relationships between these devices would results in configuration instability requiring management and maintenance of ever-changing persistent device configurations. Due to the time and cost (or lack of) active administration of these devices, any requirement to manage and maintain changing persistent device configurations on networked devices is undesirable.
Accordingly, there is a need for a device connectivity model that supports ad hoc peer networking among computing devices with preferably zero user installation or configuration experience and without persistent device configuration.
In accordance with a technology described herein, a device connectivity and control model provides an integrated set of addressing, naming, discovery and description processes (herein also termed “self-bootstrapping”) that enables automatic, dynamic and ad-hoc self-setup by devices to interoperate with other devices on a network. This permits a computing device when introduced into a network to automatically configure so as to connect and interact with other computing devices available on the network, without a user installation experience and without downloading driver software or persisting a configuration setup for connecting and interacting with such other computing devices. Upon completing interaction with such other devices, the computing device automatically releases the setup for such other devices so as to avoid persistent device configurations that might create a configuration maintenance and management burden.
The illustrated self-bootstrapping includes an integrated set of techniques organized as stacked layers, including addressing, naming, discovery, and description. In basic network addressing, a computing device introduced into a network obtains a valid address. In addition, the addressing layer of the illustrated self-bootstrapping supports assigning an address to the introduced computing device by an address server on a network if such server is available, as well as automatic self-assigning an address so as to avoid conflict with existing devices' addresses on the network where no address server is available.
In the naming layer, the illustrated self-bootstrapping includes techniques for also resolving names that identify devices, such that names that are user-friendly or more amenable to human recall and use. These naming techniques can include a name server that serves to convert a device name to its address for use in establishing a connection to the device. The techniques further enable the introduced computing device to locate such a name server without a priori knowledge of the name server's address. When assigned an address by the address server, the address server also provides the name server's address to the introduced computing device, permitting the introduced computing device to access the name server for resolving device names. On the other hand, where a name server is not available on a network, the naming techniques further include support for the introduced device to broadcast a query for a named device.
In the discovery layer, the illustrated self-bootstrapping includes techniques for discovering other devices on the network without first having their address or name, such as by type of device. The introduced computing device broadcasts a discovery request specifying a desired device type or capability. Other devices on the network monitor for such broadcast discovery requests, and respond to discovery requests that specify their device type. This enables the introduced computing device to find other devices on the network of a desired type or having a desired capability without a priori possessing an address or name of those devices. In addition, the introduced computing device announces its own presence to other devices on the network.
In the description layer, the illustrated self-bootstrapping includes techniques for devices to provide descriptions of their operational functions and services and protocols for invoking such operational functions and services. Using these techniques, the introduced computing device upon establishing a connection to another device through addressing, naming and/or discovery can then obtain descriptive information detailing how to interact with the other device so as to control its operational functions and services.
Additional features and advantages will be made apparent from the following detailed description of the illustrated embodiment which proceeds with reference to the accompanying drawings.